Deal with unwrap()

[jaytaph]

There are currently 108 unwrap() calls found in the code. They should be removed and replaced with better checking before using the unwrapped values, as this can go wrong

[Sharktheone]

This probably shouldn't be only about unwrap(), but also about panic!(). It doesn't need to be completely no_panic as i suggested in #380, since that also restricts the usage of array[index].

[jaytaph]

The panic's we can fix in the #380 ticket. It's already in the issue list. This way we keep the PR's a bit smaller. I think most of the issues are either panic and unwrap, but if we find other, we can simply add another ticket.